All our cognitive activities are about something. To access those intended things, we design networks of concepts. And while the quality of our cognition mostly depends on the quality of our conceptual designs, such designs usually further rely on semiotic systems. Thus, against a common internalist account according to which what we refer to in our cognitive activities is solely determined by our conceptual mental states, a more relevant and accurate view is that the structuring of our abstract objective networks of concepts proceeds from our concrete subjective uses of symbolic systems to intend some reference as (multi-E) cognitive agents. The purpose of this talk is to provide an overarching framework for such a semiotic-epistemological approach to conceptual engineering. To do so, I will present: first, its background (viz. conceptual engineering and semiotic epistemology); then, its theoretical core (viz. the theory of intentionality); and finally, some of its applications (namely, to the anti-representationalist/representationalist debate and to the theory of concepts).